PNEUMONIA 209 



regard to the sputum, if a bacteriological examination is 

 made, it must be remembered that it was in healthy sputum 

 that the micrococcus was iirst found, and that its presence 

 in small numbers would not therefore be conclusive. The 

 diplococci may be found in the blood a day or two before 

 the appearance of the ' rusty sputum.' 



Pathogenesis. — Both of these organisms have been found 

 to be the cause of pleurisy, endocarditis, pericarditis, 

 meningitis, etc. In its clinical features pneumonia presents 

 strong resemblances to the specific fevers, and though 

 isolated cases are most common, epidemics do occasionally 

 occur. Great alternations of heat and cold, chronic 

 alcoholism, syphilis, and plumbism, all predispose to 

 pneumonia by lowering the general health. The micro- 

 coccus of Sternberg is very fatal to mice on inoculation, 

 less so to rabbits, while pigeons and fowls are immune. 



Practical Disinfection. — The pneumococci have been 

 found in the dust of a room occupied by pneumonic 

 patients (Emmerich). In experiments by Bordoni Uffre- 

 duzzi, quoted by Sternberg, pneumonic sputum retained its 

 virulence when exposed on a cloth to direct sunlight for 

 twelve hours, and when exposed to diffused daylight only, 

 an exposure of eight weeks failed to kill the organisms; 

 this resistance was probably due to the protection afforded 

 by the dried coating of albuminous matter. (It also seems 

 probable that the organism referred to must have been the 

 diplo-bacillus of Friedlander, seeing that the diplococcus of 

 Sternberg loses its vitality so readily.) 



Sternberg found that his diplococcus was killed by two 

 hours' exposure to a very weak solution of mercuric 

 chloride (1 in 20,000). This experiment was probably made 

 on a pure culture, not on pneumonic sputum. 



Patients should expectorate into a disinfectant solution, 

 while all soiled linen should be immediately disinfected. 



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